Passerine birds in zoos: A global approach on distribution patterns and conservation breeding of threatened birds in zoological institutions

Abstract

For population management of threatened species according to the IUCN Conservation Planning Specialist Group’s One Plan Approach, knowledge about in-situ and ex-situ populations is required. To enhance the conservation of threatened birds and improve zoos’ participation in the One Plan Approach the following passerine bird data from the Zoological Information Management System (ZIMS) was analysed: individual numbers, breeding success and number of holding institutions. Species were categorised as threatened, non-threatened or not evaluated based on IUCN Red List assessments. Only 830 (~12.5%) of 6,659 recognised passerine bird species are held in ZIMS institutions worldwide, mostly in Europe, North America and Asia. Approximately 95% of the species kept globally are classified as non-threatened and ~4% (34 species) are threatened. Only 24% of the species kept successfully bred in 2021, 40% in only one zoo each. Of the threatened species, 18 reproduced. Approximately 31% of threatened species are kept in only one zoo. More than half of the species kept are represented by less than 10 individuals. Thus, conservation of threatened passerine birds in zoos needs improvement. A shift towards keeping threatened species should be considered within management programmes in human care. The expansion of conservation breeding networks should be used to secure ex-situ populations. Cooperative projects with institutions and stations in species-rich hotspots could greatly benefit passerine bird conservation by supporting future reintroductions. Thus, according to the One Plan Approach, ex-situ populations could directly contribute to in-situ protection.